AMD will bring FreeSync to HDMI early next year

Support for UHD content and DisplayPort 1.3 is coming, tooby Jeff Kampman  8:51 AM on December 8, 2015

AMD's FreeSync variable-refresh-rate technology has a lot going for it these days. Just pick out any FreeSync display you like on Newegg or Amazon and compare it to a similar display with Nvidia's G-Sync tech on board. More likely than not, the FreeSync display will be a cool Franklin or two cheaper than its G-Sync competitor. FreeSync displays tend to have more input options than G-Sync monitors, too. The green team's VRR (variable refresh-rate) screens often make do with a single DisplayPort connector. Intel has also confirmed that it'll support the standard that underpins FreeSync—VESA Adaptive-Sync—in its future products. Given how many graphics processors Intel ships in its CPUs, its backing of Adaptive-Sync could have a decisive effect on the eventual outcome of the VRR wars.

In 2016, AMD wants to make FreeSync better and more broadly available. First, it's bringing FreeSync to HDMI ports on compatible laptops and desktops. Second, it's building support for DisplayPort 1.3 (with the High Bit Rate 3 link option) into its next-generation graphics processors. DP 1.3 with HBR3 offers a major increase in potential bandwidth, and AMD will put that extra throughput to use in some exciting ways. Third, FreeSync is coming to gaming notebooks.

AMD detailed these developments for us last week at a tech summit held by its Radeon Technologies Group. Let's dive in.

FreeSync over HDMI brings buttery smoothness to more ports
We've already seen some improvements to FreeSync this year. In its Radeon Software Crimson Edition driver update, AMD enabled a feature called Low Framerate Compensation (LFC) for FreeSync displays whose maximum refresh rates are at least 2.5 times their minimum rates.

We now know that LFC's software algorithm looks at frame times and sends additional frames to the display as needed to keep motion smoother when frame rates drop below the display's minimum refresh rate. This improved method is a much-needed bit of polish, and we're glad to have it.

In its present form, FreeSync requires a DisplayPort connection to function. That's because VESA Adaptive-Sync, the technology that underpins FreeSync, is part of the DisplayPort spec. Most graphics cards have at least one DisplayPort output these days, but HDMI ports are even more common, especially on laptops. Problem is, the HDMI spec doesn't include any kind of provision for VRR tech right now, so unless you have a fancy graphics card with a lot of DisplayPort outputs, configurations like a large FreeSync Eyefinity group could be hard to set up.

AMD wanted to bring FreeSync support to HDMI ports without waiting for the next HDMI revision, so it's taking advantage of a feature called vendor-specific extensions to amend the HDMI spec for variable-refresh operation. This extension will allow present and future Radeons to talk to FreeSync-capable displays over HDMI.

Although AMD's use of vendor-specific extensions may seem like the company is jumping the gun, it assures us that the move isn't a risky one. If variable-refresh support is included in a future HDMI specification, that spec should be able to coexist peacefully with products that support AMD's extensions. The company expects that its hardware should be compatible with a future HDMI specification for VRR operation, too.

FreeSync over HDMI will begin rolling out to Radeons that can already do the VRR dance in the first quarter of 2016, but monitor makers will have to build support for the tech into new displays. AMD has already partnered with Acer, LG, and Samsung to develop a number of HDMI-FreeSync compatible monitors in a dizzying array of aspect ratios and screen sizes. The company is working with Mstar, Novatek, and Realtek to incorporate its extensions into those companies' display controller chips, as well.

FreeSync over HDMI is also coming to laptops with both an AMD APU and Radeon discrete graphics inside. The company's extensions mean that laptops with those components will be able to perform VRR over their external HDMI ports, too.